Bug - AlertGroup - li elements never unmount for timedout alerts

Describe the problem
When Alerts with a timeout are rendered inside an AlertGroup, the wrapper li element for the Alerts never unmounts when the Alerts do. This causes empty li elements to remain in the DOM.

How do you reproduce the problem?
Go to the alert timeout example and add an alert in the example. Inspect the DOM and notice that when the Alert itself unmounts, the wrapper li element remains with nothing inside of it. Add another Alert and notice that the empty li still remains in addition to a new li with the new Alert rendered inside of it.

Expected behavior
The li elements would unmount the same as the Alerts themselves

Is this issue blocking you?
List the workaround if there is one.

Screenshots
If applicable, add screenshots to help explain the issue.

What is your environment?

• OS: [e.g. iOS]
• Browser [e.g. chrome, safari]
• Version [e.g. 22]

What is your product and what release date are you targeting?

Any other information?

Inizia con il componente AlertGroup e riproduci il problema usando l’esempio di timeout degli alert. Ispeziona il DOM mentre gli Alerts soggetti a timeout scompaiono e segui come vengono renderizzati e rimossi i relativi elementi li wrapper. Il lavoro è completato quando gli Alerts soggetti a timeout non lasciano più elementi li vuoti, anche quando viene aggiunto un altro Alert.